Anther Specific Expression of the Chimeric Gene of RTS Promoter and Coding Region of β-Glucuronidase Gene in Transgenic Rice( Oryza sativa L.)

To confirm the function of the promoter of RTS gene isolated from rice by Lee et al . (1996) and partially charaterized as a tapetum specific promoter, and to test the usefulness of this promoter in obtaining male sterile plants by genetic engineering, the upstream regulatory region of RTS gene was cloned by us from Oryza sativa subsp. indica IR36 and sequenced (Fig.1). Results show that it contained 1257 nucleotides and showed a sequence similarity of 97.1% with reported sequence. The fragment from -1228 ～+25 nucleotide was fused to a coding region of β glucuronidase ( GUS ) gene and introduced into rice plant by Agrobacterium mediated gene transfer. PCR analysis and Southern blot hybridization (Plate Ⅰ 1,2) of total DNA extracted from transgenic plants indicated that the chimeric GUS gene had been integrated into the rice genome. Histochemical analysis of GUS activity showed that the expression of GUS gene, was exclusively within the anther (including tapetum, epidermis, endothecium and pollen) of transgenic rice plants(Table 1, PlateⅠ 3～5), but no expression of GUS gene was detected when the coding region of GUS gene fused to the upstream regulatory region of RTS gene from -783 ～+25 nucleotide(Table 1).